1. Field of the Invention
This invention relates to air conditioning systems to provide heated and cooled air to enclosures. Particularly the present invention concerns the control scheme for combination heat pump and solar system for use in heating and cooling an enclosure.
2. Prior Art
This control scheme was developed to provide for operation of a combination heat pump and solar heating system. Additional functions such as offpeak cooling (using the heat pump to cool a fluid during hours of reduced electric rates for providing cooling during hours of higher electric rates) are disclosed. Other functions which may be adapted to this sytem that are not included herein, include hot water heating or preheating from the solar system.
Pending patent applications entitled Integral Water-Refrigerant Air Heat Exchanger System, Ser. No. 817,945; Heat Exchanger, Ser. No. 817,946 and Heat Transfer and Storage System, Ser. No. 817,947, have been filed and are assigned to the assignee herein, Carrier Corporation. These three applications concern the use of multiple circuit coils referred to herein as the tri-x coil wherein a plate fin type heat exchanger has two complete circuits contained within it, one for a refrigerant and one for water from the storage tank. Air is passed over or through the coil in heat exchange communication with both of these fluid sources. Likewise, as shown in these pending applications, the tri-x coil need not be a plate fin type heat exchanger, but merely a heat exchanger capable of transferring heat between the three fluids, i.e., refrigerant, water and air.
Heat pump controls are known and have been disclosed in the art for many years. It is a combination system of heat pump controls and solar system controls that constitute the invention described herein.